两系杂交稻在长沙制种与繁殖的气象分析

长沙地区宜用育性转换临界光长＞１３小时３０分，临界温度为连续４天日平均气温＞２４℃，或连续２天日平均气温＞３℃，或连续４天日最低气温＞２２℃，或连续３天日最低气温＞２１℃的光温型不育系，长沙地区制种，敏感期直安排在 ８月中旬，抽穗期在 ８月下旬和 ９月初；繁殖则敏感期安排在８月下旬和９月初，抽穗期在９月上、中旬。

Analysis or Meteorology for Seed Production and Multiplication of "Two-Line" Hybrid Rice in Changsha Region

It is appropriate in Changsha to grow sterile lines of photoperiod.thermal type whose fertility changes when the critical light duration is longer than 13hr and 20 minutes and the critical temperature is as high as the daily mean temperature in successive 4 days is higher than 24 , or the daily mean temperature in successive2 days is higher than 23 , or the daily lowest temperature in successive 4 days is higher than 22 , or the daily lowest temperature in successive 3 days is higher than 21 . If seed production is conducted. it is better then the sensitive stage is in middle August and the heading stage is in late August or early September. If multiplication is done. it is better when the sensitive stage is in late August or early September and the heading stage is in early or middle September.